#set( $symbol_pound = '#' )
#set( $symbol_dollar = '$' )
#set( $symbol_escape = '\' )
package ${package}.utils;

import java.math.BigDecimal;

public class GeoUtils {
    /**
     * 默认地球半径
     */
    private static double EARTH_RADIUS = 6371000;//赤道半径(单位m)

    /**
     * 转化为弧度(rad)
     * */
    private static double rad(double d)
    {
        return d * Math.PI / 180.0;
    }
    /**
     * @param lon1 第一点的精度
     * @param lat1 第一点的纬度
     * @param lon2 第二点的精度
     * @param lat2 第二点的纬度
     * @return 返回的距离，单位m
     * */
    public static BigDecimal GetDistance(double lon1,double lat1,double lon2, double lat2, int scale) {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lon1) - rad(lon2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2) + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS;
        return new BigDecimal(String.valueOf(s)).setScale(scale, BigDecimal.ROUND_HALF_UP);
    }
}
